Tectonic Plates Flashcards
What is Pangaea?
Super continent
What evidence did wegener use to validate his continental drift theory?
Look alike animals and plant fossils on different continents
What is sea floor spreading?
New oceanic crust formed through volcanic activity
Who was Harry Hess?
U.S. Geologist theory of plate tectonics
What is the evidence for sea floor spreading?
New islands
Tectonic plates are part of the lithosphere and sit on the asthenosphere true or false
Tectonic plates are part of the lithosphere and sit on the asthenosphere
True
What is the asthenosphere?
It is part of the mantle
What is responsible for the movements of tectonic plates?
Convections currents in the asthenosphere
What is magma?
Magma is molten rock trapped within the earth
What is lava?
Lava is molten rock that has reached the earths surface
What are the two types of crust?
Continental, oceanic
What are the layers of the earth?
Inner core
Outer core
Mantle
Crust
What are diverging boundaries?
The line between tectonic plates moving away from each other
What are converging boundaries?
The line between tectonic plates moving towards each other
What are transform boundaries?
The line between tectonic plates moving along side each other
What is a subduction zone?
Where plates meets
Why do volcanoes and earthquakes align with plate boundaries?
Form where plates pull away from each other
Why does Australia not have many serious earthquakes?w
One big tectonic plate no fault lines
How far do tectonic plates move in a year
2-5cm
What are the materials that come out of volcanoes?
Gas
Lava
Define an earthquake
Sudden movement of earths crust caused by the release of stress
Define p waves
Elastic waves
What are S waves?
Secondary waves
They cause the rocks they pass through to change in shape.
What are surface waves
Mechanical waves
Which seismic waves travels the fastest?
P waves
What is the epicentre of an earthquake?
Point on the earths surface directly above the focus of an earthquake
What is the focus of an earthquake?
Place where earthquake begins
What is the strongest earthquake recorded?
9.5 chile earthquake
What is a seismograph, seismograph?
Seismograph is the equipment that records the earths movements, a seismograph is the visual record
What makes tsunamis different from normal waves?
The wave of a tsunami is much longer than a conventional wave .
A tsunami travels up to 900 km/ hr and a conventional wave travels up to 90 km /hr
What is continental drift?
The movement of the earths continents relative to each other
